Tonight's mayoral debate will be the first opportunity for Democrat Bill de Blasio and Republican Joe Lhota to square off before New York City's electorate.

The debate, the first of three during the general election, comes amid a staid race that has de Blasio, the city's public advocate, posting a 44-percentage-point lead in the most recent poll over Lhota, a former MTA chief and deputy mayor under Rudy Giuliani.

Political experts from both parties say the televised debate, hosted by WABC/7, is an opportunity for Lhota to close the gap by emphasizing his managerial strengths and budget knowledge, while de Blasio needs to stay on a message that has proved successful so far.

"Lhota is the little guy with a slingshot right now," said Richard Flanagan, associate professor of political science at the College of Staten Island. "He can land a few stones off Goliath's forehead -- not enough to wound him mortally, but enough to create a little interest this week about his campaign."

While this is Lhota's first run for office, De Blasio has a lot of debates under his belt, having participated between 60-70 candidate forums, by his count. De Blasio, however, declined to participate in a NY1 debate last week alongside Lhota and independent candidate Adolfo Carrión, a former Bronx borough president.

"I practice a lot making sure I get the clear, precise vision out of where I want to take this city," de Blasio said Sunday while campaigning in Flushing. "And as everyone knows, it focuses on addressing the inequalities that I think are rampant in this city and need to be changed."

Lhota, meanwhile, said the debate will be a turning point in his campaign because of their contrasting visions for the city.

"This will the first chance that Bill de Blasio will be standing next to me, Joe Lhota, talking about our visions for the future of the city of New York," Lhota said Monday at the Columbus Day parade. "New Yorkers need to see that stark difference and our different philosophies and our different approaches."

While playing up his experience, Lhota must also criticize de Blasio beyond the types of jabs thrown from the campaign trail about going back to the "bad old days" of the David Dinkins administration or honeymoons in Cuba, said Ryan James Girdusky, a GOP campaign consultant in Queens.

"It has to look like [de Blasio's] vision is out of touch," he said. "He's got to stop pinching and start punching. And he's got to stop running against Dinkins. That model is over."

Democratic political operatives predicted Lhota won't land a decisive blow that knocks de Blasio off his game and turns the campaign around.

Mark Green, a former public advocate, said de Blasio has his narrative down and has the chops to stay cool. If Lhota focuses on his background, he could narrow the gap for a decent showing at the polls.

"While Lhota understandably feels the pressure to score on three straight Hail Mary passes, it's not possible," said Green, who debated Michael Bloomberg and de Blasio in unsucceful runs for mayor and public advocate in 2001 and 2008. "Instead, he should stay calm and positive about his own strengths and not throw dung at de Blasio."